Neutral atoms are among the leading technologies for advanced analog and digital quantum simulations and have recently emerged as a highly promising platform for quantum computing [1]}, [2]}, [3]}, [4]}, [5]}.
Near defect-free arrays of alkali-metal and alkali-earth(-like) atoms can be routinely prepared at sub-millikelvin temperatures in optical tweezers and in optical lattices in arbitrary dimensions [6]}, [7]}, [8]}, [9]}, [10]}.
Fast two-qubit gates can be achieved by encoding quantum information in the internal – usually electronic ground – states of individual atoms (or collective excitations of atomic ensembles [5]}) while strong interactions can be mediated by electronically highly excited Rydberg states, which can be controlled using laser fields [see Fig. REF (a)]. In the original scheme [12]}, the accumulation of relevant phase shifts in two-qubit quantum gates is facilitated by the so-called “Rydberg blockade” mechanism, whereby one laser-excited atom
shifts the Rydberg states of neighboring atoms out of resonance due to strong Rydberg-Rydberg interactions – a process that can be readily generalized to \(k\) -qubit gates, in principle [13]}, [14]}. Two-qubit entangling gates have been implemented in several experiments [15]}, [16]}, [17]}, [18]}, [19]}, [20]}, achieving fidelities up to 99.1%. [20]}.
